Toby, you are too modest.
I arrived about an hour after Toby made a start which found him finishing off the handbrake cables fitment. New front discs and pads were also in place as were the new front brake hoses, leaving just the rears to do. As Toby says, the MOT tester needs to explain how the old hoses were hosed exactly as apart from the rough cut end done while removing, they looked in very good condition - perhaps they were ballooning in use? Anyway Toby, if you're looking for another place to get your MOT's done, try Chessing Tyres, Christchurch (though I think they've just changed their name to Kwik Fit).
Unfortunately his battery was far too weak to start the car and my booster pack made little difference so we fitted my spare battery and it fired up straight away. It was then that I noticed the fans were running half speed - not sure what's happening there but I suspect it may have been a contributor of his battery problem. We ignored it for the time being to get on with the rear discs.
I must take some if not all the blame for the sheared bolt as I misread the Haynes section by following the procedure for caliper removal which requires the supply pipes to be disconnected - whereas disc removal does not! It wasn't easy getting a purchase on the union nut so I suggested we removed the shields. Then the distractions began as one bolt sheared. Toby drilled out most of it but remnants refused to fall out. A quick trip back home to get some easy-outs but they didn't live up to their name

I think either a nut and bolt or a thread tap should sort it. I'm in total agreement with you on this, red-dwarfers.
We wasted too much time trying different methods to no avail so after discussing possible workarounds/bodges, we got on with replacing the discs and pads and bleeding the brakes (his LHM was very, very clean I must say).
The haynes book confused us both on how to set the handbrake cable but once all four tyres were back on, a test against engine power proved they were effective at least.
Getting back to the battery, the charging system was tested as ok, giving just over 14V and then the current drain was tested as being 20mV - 50mV. But as I refitted the terminal noticed the clamp wasn't tightening - closer inspection showed it had cracked completely in two. Hopefully, we have now identified the battery failure causes.
We were both tired and hungry at the end of this, with Toby getting leg cramps and me suffering neck muscle spasm said it was time to finish. Despite the setbacks, we both got some good experience under our belts now.